Exercise has a primary importance in the course of recovery and rehabilitation from orthopedic surgeries, arthroscopies, skeletal traumas, and muscular injuries among patients in the general population. Exercise therapy is especially important among professional and amateur athletes. Efficient monitoring of therapy is highly desirable to deliver managed healthcare at high quality and reasonable costs, while ensuring the active participation of the patient.
Amateur athletes are found in high numbers among the population served by managed care organizations. Currently, an estimated 44 million people in the US participate in some form of exercise or sport. Every year approximately 35 percent of this population (15.4 million) experience a musculo-skeletal injury that is best treated using rehabilitative exercise, or surgical repair and physical therapy.
In addition, exercise is gaining acceptance as xe2x80x98the fountain of youthxe2x80x9d by our aging population. Many middle-aged people participate in various athletics. These people contribute to the population that is being treated for orthopedic injuries by managed care organizations.
Much medical and physiologic research shows a direct relationship between exercise and faster recovery in rehabilitation from orthopedic injuries, traumas, and surgeries. The period of time for recovery is often extended if exercise therapy does not proceed according to a prescribed duration, intensity, and frequency. Indeed, full recovery may not occur or the quality of the recovery is diminished if the exercise regimen is not pursued and fulfilled according to plan, or if exercise is not formally assigned by the caregiver.
A patient in the process of exercise therapy is directed to exercise at home, without supervision. Monitoring of the exercise therapy takes place at infrequent visits to a health care provider. Often monitoring indicates that the unsupervised exercise therapy is insufficient to achieve a quality recovery. The health care provider can detect that the unsupervised exercise therapy is insufficient but cannot determine how the therapy is lacking. The health care provider cannot determine whether the patient is failing to fulfill the prescribed exercise regiment or whether the patient is diligently performing the prescribed therapy but simply has a diminished capacity for exercise.
To date, no inexpensive technique is available for encouraging and monitoring a patient""s pursuit of unsupervised physical and exercise therapy assignments following an injury, trauma, or surgery. Without the presence of a physical therapist, a trainer, or a $50,000.00 cybernetic, three-dimensional sensor/recorder/evaluation system, a patient""s practice of an assigned physical or rehabilitation therapy is impossible to monitor. The patient is to be monitored to determine: (1) whether the patient is engaging in the exercise therapy as often as directed; (2) whether the patient is performing no more and no fewer repetitions than are assigned; and (3) whether the patient performs the exercises within a directed range of motion without significant discomfort. The range of motion typically increases over time as healing progresses with observable measures of improvement. The measures of improvement include decreased swelling, greater joint mobility, and increased muscular strength. However, the degree of improvement that permits a greater range of motion and function, the key issues in recovery, may be observed as infrequently as every seven to fourteen days over a period of several months. Unfortunately, the cost of more frequent visits to see a physician or physical therapist would be unacceptable for a managed care organization.
A further problem with unsupervised therapy and rehabilitation is the possibility of an adverse outcome. A normal scenario following the surgical repair of a trauma, a knee arthroscopy, an arthrotomy for a torn meniscus, or a surgery such as total hip arthroplasty, for example, is a healing with a predictable result of some degree of success. The normal scenario generally occurs when the treatment is biomechanically correct and appropriate, and all of the parameters of exercise are satisfied so that a normal recovery in light of the severity of the injury or the extent of the surgery. If the parameters of exercise or rehabilitation are not satisfied, an equally predictable outcome is a failure to recover within an acceptable xe2x80x9cnormalxe2x80x9d standard.
A failure to recover muscular function and range of motion can become the subject of a lawsuit in which a patient claims that the surgical repair, arthroscopy, reconstruction, or the like was inadequately or incorrectly performed. A patient may bring suit against the institution treating the patient, the healthcare provider, and all persons involved in the patient""s care. If no evidence of infection, neurologic damage, misalignment of bone ends or implant components, or other measurable and observable cause occurs to explain the functional failure, then inadequate rehabilitation may be deemed a cause of the patient""s disability. For example, a patient may receive no physical therapy but rather is instructed to perform unsupervised rehabilitative exercises at home with periodic (generally weekly or biweekly) clinical visits to monitor the patient""s progress. The patient may claim that the exercises did not help and that physical therapy was needed. A managed care organization or health care provider has little evidence supporting the premise that a prescribed exercise regimen is as effective as physical therapy. The managed care organization or health care provider has little evidence supporting the premise that the unsupervised exercise or therapy prescribed is appropriate but that the patient did not suitably follow directions and perform a suitable therapy regimen.
What is needed is a system and operating method for monitoring the unsupervised therapy of a patient that is simple, efficient, and cost-effective. What is further needed is a system and operating method that supplies information regarding the duration, intensity, and frequency of exercise therapy and rehabilitation.
A flexure measurement device measures the flexure of a flexing body part thereby describing a range of motion of the body part. The flexure measurement device includes a flexible member and a sensor for detecting a change in proportion of the flexible member in response to flexing of the flexible member. In one example, a flexure measurement device measures a change in a length dimension of an elongated flexible member. The length dimension is measured using transmitted signals in which a light source directs a light beam across an array of light sensors. A change in length causes a light source to pivot, thereby chanoing the light sensors upon which the light beam impinges. The flexure measurement device determines a position in the array of light sensors at which the illumination changes from light to dark to produce a flexure angle measurement.
In one embodiment of a flexure measurement device, a flexible member is connected to a plurality of small blocks. The individual blocks include an aperture for passing a line such as a fixed-length string and extending parallel to the flexible member. The blocks and apertures form a constant offset from the longitudinal body of the flexible member to the pathway of the string. The string is attached at a first end to a first end of the flexible member. When the flexible member is flexed, a second end of the string moves with respect to the flexible member. The displacement of the second end of the string is directly proportional to an angle formed by the first and second ends of the flexible member.
In accordance with another embodiment of the present invention, a flexure measurement device includes a sensor for measuring displacement including a plurality of light sensors and a light emitter. The light emitter is connected to a moveable assembly, such as a hinged assembly, in which a fixed portion of the moveable assembly, such as a hinge, is firmly connected to a flexible member having a first end and a second end. A fixed-length line has a first end affixed to the first end of the flexible member and a second end affixed to a moveable portion of the hinged assembly. The light emitter is also connected to the moveable portion of the hinged assembly and configured to produce a narrow beam. The fixed-length line moves with respect to the flexible member when the flexible member is flexed, causing the moveable portion of the hinged assembly and the light emitter to move, sweeping across the plurality of light sensors in the manner of a searchlight and activating particular light sensors when illuminated. The light sensors generate a digital output signal that is proportional to the movement of the hinged assembly and the motion of the flexible member. Gain of the digital output signal is adjusted by changing the point of attachment of a moving structure such as the fixed-length line with respect to the arm and by adjusting the distance from the light emitter to the plurality of light sensors.
In some embodiments, the light emitter is a light-emitting diode (LED) that is masked to generate a narrow illumination beam, and the plurality of light sensors is a charge-coupled device (CCD) array.
In some embodiments, a slide attachment is used rather than a pivot for attaching the light source. In some embodiments, the light source is held fixed while the light sensors are moved.
In another aspect of the present invention, a biomechanical monitoring system includes a flexure measurement device for monitoring a series of joint flexure measurements. The flexure measurement device transmits the joint flexure measurements via an interface to a database utilizing the Internet.
The described flexure measurement device, system, and operating method have many advantages. The flexure measurement device advantageously generates highly stable and repeatable measurements of the angle of a joint without aligning the device with the joint. The flexure measurement device advantageously is constructed in small, light, highly-portable forms for convenient usage in exercise applications and physical therapy applications. The flexure measurement device advantageously gives patients direct control over rehabilitation, avoiding soreness and injury that can accompany overly aggressive pursuit of exercise and ensuring compliance with a progression in range of motion, duration, intensity, and frequency when the process causes transitory discomfort.